1,720,974 research outputs found

    The role of central-mediated hepatic responses in the obesity-induced impediment of hepatic regeneration

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    摂食に伴い増加するインスリンや様々な栄養素が、中枢神経に作用し、迷走神経・クッパー細胞を介して、肝臓IL-6/STAT3シグナルを活性化することを見出している。一方で、転写因子STAT3は、抗アポトーシスおよび細胞増殖関連遺伝子の発現誘導を介し、肝再生のマスターレギュレーターとして重要な働きを担っている。本研究において、中枢神経による迷走神経制御と肝臓STAT3活性化の仕組みを明らかにするとともに、その仕組みがインスリン抵抗性・肥満状態では障害されることを見出している。肥満・インスリン抵抗性による中枢神経性肝臓機能調節の異常が、肝再生障害と相関する可能性を示唆するものである。Brain-mediated hepatic responses, including gluconeogenic suppression, are mediated by the vagus nerve and hepatic IL-6/STAT3 activation. Meanwhile, hepatic STAT3 is known as the master regulator of hepatic regeneration, controlling the expressions of anti-apoptotic genes and cell-cycle related genes. In this project, we elucidate the mechanism of how brain regulates the vagus nerve and hepatic STAT3 activation. Further, we have found that the central-mediated hepatic responses are impeded in obesity. While hepatic regeneration is impaired in insulin-resistance and obesity, the impeded brain-mediated hepatic responses may be related to the obesity-induced dysfunction of hepatic regeneration.研究課題/領域番号:26670599, 研究期間(年度):2014-04-01 – 2016-03-31出典:研究課題「NAFLDでの肝切除後肝再生障害における中枢神経性肝臓機能調節の有用性の解明」課題番号:26670599 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-26670599/26670599seika/)を加工して作成金沢大学新学術創成研究機構research repor

    Understanding the mechanism of how central action of amino acids suppresses hepatic glucose production

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    代表者らは、ヒスチジンが中枢神経ヒスタミン作用に依存して肝糖産生を抑制し、血糖減少作用を発揮する事を見出している。ヒスチジンの耐糖能異常改善食材としての有用性が期待されるが、中枢神経ヒスチジン作用の肝臓での分子メカニズムは明らかではない。本研究では、中枢神経ヒスチジン作用は、迷走神経を介し、肝臓STAT3シグナルを活性化し、肝糖新生系酵素の遺伝子発現を抑制することを明らかにした。迷走神経は、クッパー細胞α7型ニコチン性アセチルコリン受容体を介して、肝臓STAT3シグナルを抑制しており、中枢神経ヒスチジン作用が、迷走神経活動を抑制することにより、肝臓STAT3シグナルを活性化することを見出した。We have reported that histidine administration reduced blood glucose levels in mice, by suppressing hepatic glucose production via central histamine action. Although histidine is expected to be a candidate for blood glucose-lowering nutrient, the precise mechanism of how central histidine suppresses hepatic glucose production remains unclear. Here, we found that central action of histidine and histamine decreased hepatic gluconeogenic genes by activating hepatic STAT3 signaling via the vagus nerve. Moreover, we found that the vagus nerve suppressed hepatic IL-6/STAT3 signaling via the α7-nicotinic acetylcholine receptors, and that central insulin action activated hepatic IL-6/STAT3 signaling by suppressing vagal activity.研究課題/領域番号:26282022, 研究期間(年度):2014-04-01 – 2017-03-31出典:「生活習慣病予防におけるアミノ酸の中枢性肝糖産生抑制作用の有用性の解明」研究成果報告書 課題番号26282022 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-26282022/26282022seika/)を加工して作成金沢大学新学術創成研究機構research repor

    Investigation of the role of cell-cycle regulatory mechanism in hepatic glucose metabolism

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    Cyclin D1は、細胞周期調節のみならず、様々な転写因子の活性を制御している。肝臓Cyclin D1の遺伝子および蛋白発現は、絶食に伴い減少し、食事摂取後に増加した。培養肝細胞を用いた糖新生酵素プロモーター解析では、Cyclin D1の遺伝子導入により肝糖新生酵素遺伝子発現プロモーター活性が、減少した。これらの結果は、肝臓Cyclin D1が糖代謝制御に何らかの役割を果たす可能性を示している。Cyclin D1 is known to regulate not only cell-cycle but also activity of various transcription factors. Through this investigation, we have uncoverd an alteration in hepatic cyclin D1 expression by fasting and refeeding. Fasting reduced the expression of cyclin D1 gene and protein and refeeding increased. We have also clarified that cyclin D1 suppressed the promoter activity of gluconeogenic gene in H42E hepatoma cell. These results suggest that hepatic cyclin D1 would plays a certain role in the regulation of glucose metabolism.出典:研究課題「肝細胞周期調節因子の肝糖脂質代謝における役割」課題番号21790868 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-21790868/21790868seika/)を加工して作成金沢大学新学術創成研究機構research repor

    Role of histidine in glucose metabolism

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    肝臓STAT3は、中枢神経性肝糖新生調節の肝臓作用分子であり、活性化に伴い肝糖産生を抑制する。我々は、肝臓STAT3が、タンパク質摂取に伴う高ヒスチジン血症に伴い、活性化される事を見出した。ヒスチジン投与により肝臓STAT3は活性化し、インスリンによる肝糖産生抑制を増強する。ヒスチジンによる肝糖産生調節作用は、中枢神経ヒスタミンH1受容体阻害により消失した。ヒスチジンが、インスリンと同様に、中枢神経ヒスタミン作用を介して、肝臓STAT3を活性化し、肝糖新生酵素遺伝子発現を抑制する事を示唆している。中枢神経で、ヒスチジンとインスリンの作用は、肝糖産生抑制に関しては相加的に作用することも見出した。We previously revealed that hepatic STAT3 decreases the expression of hepatic gluconeogenic enzymes and suppresses hepatic glucose production. Here, we show that increased plasma histidine caused by protein intake resulted in hepatic STAT3 activation. Intravenous and intracerebroventricular administration of histidine also activated hepatic STAT3 and augmented the suppression of hepatic glucose production by insulin. Inhibition of hepatic glucose production by histidine was blocked by inhibiting histamine H1receptors in the central nervous system. Therefore, histidine activates hepatic STAT3 and suppresses hepatic glucose production via central histamine action. In the central nervous system, the mechanisms of histidine and insulin are independent, but have additive inhibitory effects on hepatic glucose prodcution. This suggests that central histidine-mediated suppressive action on hepatic glucose production is a potential target for the treatment of type 2 diabetes.研究課題/領域番号:23300274, 研究期間(年度):2011-04-01 – 2014-03-31出典:「ヒスチジン誘導体の糖代謝における役割」研究成果報告書 課題番号23300274 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-23300274/23300274seika/)を加工して作成research repor

    Investigation of soy protein isolate in whole body glucose metabolism

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    大豆たんぱく(SPI)が、インスリン抵抗性を改善する可能性が指摘されていることから、カゼインを主たる蛋白質源とする対照高脂肪食と、カゼインをSPIに置換したSPI高脂肪食を4週間投与し、マウスモデルでの投与実験を行い、糖代謝パラメーターを測定した。 体重・血糖値・血中インスリン値のいずれについても、SPI食および対照食の2群間において、明らかな差を認めなかった。投与後4週間で実施した糖負荷試験においても、明らかな耐糖能の変化を見出さなかった。4週間の高脂肪食負荷に対しては、SPIとカゼインの間に、必ずしも明らかな個体糖代謝・肝糖産生に及ぼす作用に差がない可能性が示唆された。Soy protein isolate (SPI) is known to improve insulin resistance. Therefore, we measured parameters of whole body glucose metabolism in mice fed with high fat (HF) diet containing casein or SPI as main protein source for 4 weeks. Between mice fed with casein-HF diet and with SPI-HF diet, there is no difference in body weight, blood glucose levels, and plasma insulin levels. At 4 weeks after the initiation of HF feeding, we performed glucose tolerance test to evaluate whole body glucose tolerance between these two group and found no difference of glucose tolerance in these two groups. These findings suggested thatSPI has little effect to improve insulin resistance under the condition of 4 week HF feeding.研究課題/領域番号:24650487, 研究期間(年度):2012-04-01 – 2014-03-31出典:「リアルタイムモニタリングによる蛋白質摂取の肝糖代謝への効果の検討」研究成果報告書 課題番号24650487 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-24650487/24650487seika/)を加工して作成research repor

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    生活習慣病の複雑な病態を説明する迷走神経異常の解明

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    非アルコール性脂肪性肝炎(NASH)は、インスリン抵抗性に伴い、慢性肝障害を来す生活習慣病である。本研究では、α7型ニコチン受容体(A7nAchR)の欠損マウス(A7KO)を用い、NASH発症への迷走神経作用の役割を検討した。A7KOに対し、食餌性NASH誘導を行い、肝臓炎症・線維化への作用を検討した。AD投与で、A7KOでは、血漿トランスアミナーゼレベル上昇が増加した。A7KOは、AD投与下で、肝臓炎症性ケモカイン遺伝子および肝臓線維化関連遺伝子の発現の増加、肝線維化の増悪を呈した。これらの結果から、A7nAchR作用の障害が、NASHを増悪させることを明らかにした。Nonalcoholic steatohepatitis (NASH), which occurs in association with insulin resistance and hepatic fat accumulation, confers high risk of liver fibrosis and chronic liver injury. In this study, using systemic α7 nicotinic acetylcholine receptor (A7nAchR) knockout mice (A7KO), we investigated the role of A7nAchR in NASH. Specifically, A7KO mice were fed an atherogenic high-fat diet (AD), which induce NASH. Hepatic triglyceride accumulation and elevated plasma transaminase levels were observed in AD mice, and we found the plasma transaminase level increase was higher in A7KO mice than in control mice. A7KO mice fed an AD showed significant upregulation of fibrosis-related genes and proinflammatory-cytokine genes in the liver. Histological analysis with Sirius red revealed that AD exacerbated liver fibrosis in A7KO mice. From these findings, it is clear that A7nAchR deficiency exacerbates hepatitis and fibrosis due to hepatic fat accumulation.研究課題/領域番号:18KT0020, 研究期間(年度):2018-07-18 – 2021-03-31出典:「生活習慣病の複雑な病態を説明する迷走神経異常の解明」研究成果報告書 課題番号18KT0020 (KAKEN:科学研究費助成事業データベース(国立情報学研究所)) (https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-18KT0020/18KT0020seika/)を加工して作成research repor
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